Pin jax to 0.11.0 in CI -- jax 0.11.1 hangs the fori_loop cells on CPU

jax 0.11.1 (2026-08-17) regresses lax.fori_loop on the CPU path.
numpy_vs_numba_vs_jax's jax cells jit with device=cpu, so the
regression bites even on this repo's GPU runners; the unpinned
'pip install -U jax[cuda13]' would resolve the broken release at the
next Monday cache rebuild (2026-08-24). Executed in 8.18s under 0.11.0
on 2026-08-17; the fr/fa siblings measured >1800s under 0.11.1. Full
evidence and the family-wide exposure map are recorded in
QuantEcon/workspace-lectures#49.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: mmcky

.github/workflows/cache.yml

@@ -21,7 +21,13 @@ jobs:
       - name: Install JAX and Numpyro
         shell: bash -l {0}
         run: |
-          pip install -U "jax[cuda13]"
+          # Pinned: jax 0.11.1 (2026-08-17) hangs numpy_vs_numba_vs_jax's
+          # lax.fori_loop cells -- they jit with device=cpu, so the CPU-path
+          # regression bites even on these GPU runners. Context is recorded in
+          # QuantEcon/workspace-lectures#49. With jax already present, the
+          # lecture's unpinned `!pip install quantecon jax` cell is satisfied
+          # and does not upgrade.
+          pip install "jax[cuda13]==0.11.0"
           pip install numpyro
           python scripts/test-jax-install.py
       - name: Check nvidia drivers

.github/workflows/ci.yml

@@ -26,7 +26,13 @@ jobs:
       - name: Install JAX and Numpyro
         shell: bash -l {0}
         run: |
-          pip install -U "jax[cuda13]"
+          # Pinned: jax 0.11.1 (2026-08-17) hangs numpy_vs_numba_vs_jax's
+          # lax.fori_loop cells -- they jit with device=cpu, so the CPU-path
+          # regression bites even on these GPU runners. Context is recorded in
+          # QuantEcon/workspace-lectures#49. With jax already present, the
+          # lecture's unpinned `!pip install quantecon jax` cell is satisfied
+          # and does not upgrade.
+          pip install "jax[cuda13]==0.11.0"
           pip install numpyro
           python scripts/test-jax-install.py
       - name: Install latex dependencies

.github/workflows/publish.yml

@@ -38,7 +38,13 @@ jobs:
       - name: Install JAX and Numpyro
         shell: bash -l {0}
         run: |
-          pip install -U "jax[cuda13]"
+          # Pinned: jax 0.11.1 (2026-08-17) hangs numpy_vs_numba_vs_jax's
+          # lax.fori_loop cells -- they jit with device=cpu, so the CPU-path
+          # regression bites even on these GPU runners. Context is recorded in
+          # QuantEcon/workspace-lectures#49. With jax already present, the
+          # lecture's unpinned `!pip install quantecon jax` cell is satisfied
+          # and does not upgrade.
+          pip install "jax[cuda13]==0.11.0"
           pip install numpyro
           python scripts/test-jax-install.py
       - name: Check nvidia drivers